![Johannes Berg](/assets/img/avatar_default.png)
Reinette found the reason for the warnings that happened occasionally when a hw-offloaded scan finished; her description of the problem: mac80211 will defer the handling of scan requests if it is busy with management work at the time. The scan requests are deferred and run after the work has completed. When this occurs there are currently two problems. * The scan request for hardware scan is not fully populated with the band and channels to scan not initialized. * When the scan is queued the state is not correctly updated to reflect that a scan is in progress. The problem here is that when the driver completes the scan and calls ieee80211_scan_completed() a warning will be triggered since mac80211 was not aware that a scan was in progress. The reason is that the queued scan work will start the hw scan right away when the hw_scan_req struct has already been allocated. However, in the first pass it will not have been filled, which happens at the same time as setting the bits. To fix this, simply move the allocation after the pending work test as well, so that the first iteration of the scan work will call __ieee80211_start_scan() even in the hardware scan case. Bug-identified-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
816 lines
22 KiB
C
816 lines
22 KiB
C
/*
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* Scanning implementation
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*
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* Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
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* Copyright 2004, Instant802 Networks, Inc.
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* Copyright 2005, Devicescape Software, Inc.
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* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
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* Copyright 2007, Michael Wu <flamingice@sourmilk.net>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/wireless.h>
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#include <linux/if_arp.h>
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#include <linux/rtnetlink.h>
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#include <net/mac80211.h>
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#include "ieee80211_i.h"
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#include "driver-ops.h"
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#include "mesh.h"
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#define IEEE80211_PROBE_DELAY (HZ / 33)
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#define IEEE80211_CHANNEL_TIME (HZ / 33)
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#define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 8)
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struct ieee80211_bss *
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ieee80211_rx_bss_get(struct ieee80211_local *local, u8 *bssid, int freq,
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u8 *ssid, u8 ssid_len)
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{
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return (void *)cfg80211_get_bss(local->hw.wiphy,
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ieee80211_get_channel(local->hw.wiphy,
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freq),
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bssid, ssid, ssid_len,
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0, 0);
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}
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static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss)
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{
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struct ieee80211_bss *bss = (void *)cbss;
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kfree(bss_mesh_id(bss));
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kfree(bss_mesh_cfg(bss));
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}
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void ieee80211_rx_bss_put(struct ieee80211_local *local,
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struct ieee80211_bss *bss)
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{
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cfg80211_put_bss((struct cfg80211_bss *)bss);
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}
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struct ieee80211_bss *
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ieee80211_bss_info_update(struct ieee80211_local *local,
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struct ieee80211_rx_status *rx_status,
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struct ieee80211_mgmt *mgmt,
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size_t len,
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struct ieee802_11_elems *elems,
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struct ieee80211_channel *channel,
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bool beacon)
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{
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struct ieee80211_bss *bss;
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int clen;
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s32 signal = 0;
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if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
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signal = rx_status->signal * 100;
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else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
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signal = (rx_status->signal * 100) / local->hw.max_signal;
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bss = (void *)cfg80211_inform_bss_frame(local->hw.wiphy, channel,
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mgmt, len, signal, GFP_ATOMIC);
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if (!bss)
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return NULL;
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bss->cbss.free_priv = ieee80211_rx_bss_free;
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/* save the ERP value so that it is available at association time */
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if (elems->erp_info && elems->erp_info_len >= 1) {
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bss->erp_value = elems->erp_info[0];
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bss->has_erp_value = 1;
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}
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if (elems->tim) {
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struct ieee80211_tim_ie *tim_ie =
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(struct ieee80211_tim_ie *)elems->tim;
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bss->dtim_period = tim_ie->dtim_period;
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}
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/* set default value for buggy AP/no TIM element */
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if (bss->dtim_period == 0)
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bss->dtim_period = 1;
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bss->supp_rates_len = 0;
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if (elems->supp_rates) {
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clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
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if (clen > elems->supp_rates_len)
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clen = elems->supp_rates_len;
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memcpy(&bss->supp_rates[bss->supp_rates_len], elems->supp_rates,
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clen);
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bss->supp_rates_len += clen;
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}
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if (elems->ext_supp_rates) {
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clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
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if (clen > elems->ext_supp_rates_len)
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clen = elems->ext_supp_rates_len;
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memcpy(&bss->supp_rates[bss->supp_rates_len],
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elems->ext_supp_rates, clen);
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bss->supp_rates_len += clen;
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}
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bss->wmm_used = elems->wmm_param || elems->wmm_info;
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if (!beacon)
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bss->last_probe_resp = jiffies;
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return bss;
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}
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ieee80211_rx_result
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ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
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{
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struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
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struct ieee80211_mgmt *mgmt;
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struct ieee80211_bss *bss;
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u8 *elements;
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struct ieee80211_channel *channel;
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size_t baselen;
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int freq;
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__le16 fc;
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bool presp, beacon = false;
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struct ieee802_11_elems elems;
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if (skb->len < 2)
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return RX_DROP_UNUSABLE;
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mgmt = (struct ieee80211_mgmt *) skb->data;
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fc = mgmt->frame_control;
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if (ieee80211_is_ctl(fc))
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return RX_CONTINUE;
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if (skb->len < 24)
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return RX_DROP_MONITOR;
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presp = ieee80211_is_probe_resp(fc);
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if (presp) {
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/* ignore ProbeResp to foreign address */
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if (memcmp(mgmt->da, sdata->dev->dev_addr, ETH_ALEN))
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return RX_DROP_MONITOR;
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presp = true;
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elements = mgmt->u.probe_resp.variable;
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baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
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} else {
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beacon = ieee80211_is_beacon(fc);
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baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
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elements = mgmt->u.beacon.variable;
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}
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if (!presp && !beacon)
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return RX_CONTINUE;
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if (baselen > skb->len)
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return RX_DROP_MONITOR;
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ieee802_11_parse_elems(elements, skb->len - baselen, &elems);
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if (elems.ds_params && elems.ds_params_len == 1)
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freq = ieee80211_channel_to_frequency(elems.ds_params[0]);
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else
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freq = rx_status->freq;
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channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq);
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if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
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return RX_DROP_MONITOR;
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bss = ieee80211_bss_info_update(sdata->local, rx_status,
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mgmt, skb->len, &elems,
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channel, beacon);
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if (bss)
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ieee80211_rx_bss_put(sdata->local, bss);
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dev_kfree_skb(skb);
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return RX_QUEUED;
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}
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/* return false if no more work */
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static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
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{
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struct cfg80211_scan_request *req = local->scan_req;
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enum ieee80211_band band;
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int i, ielen, n_chans;
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do {
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if (local->hw_scan_band == IEEE80211_NUM_BANDS)
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return false;
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band = local->hw_scan_band;
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n_chans = 0;
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for (i = 0; i < req->n_channels; i++) {
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if (req->channels[i]->band == band) {
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local->hw_scan_req->channels[n_chans] =
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req->channels[i];
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n_chans++;
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}
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}
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local->hw_scan_band++;
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} while (!n_chans);
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local->hw_scan_req->n_channels = n_chans;
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ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie,
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req->ie, req->ie_len, band);
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local->hw_scan_req->ie_len = ielen;
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return true;
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}
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/*
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* inform AP that we will go to sleep so that it will buffer the frames
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* while we scan
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*/
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static void ieee80211_scan_ps_enable(struct ieee80211_sub_if_data *sdata)
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{
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struct ieee80211_local *local = sdata->local;
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local->scan_ps_enabled = false;
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/* FIXME: what to do when local->pspolling is true? */
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del_timer_sync(&local->dynamic_ps_timer);
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cancel_work_sync(&local->dynamic_ps_enable_work);
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if (local->hw.conf.flags & IEEE80211_CONF_PS) {
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local->scan_ps_enabled = true;
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local->hw.conf.flags &= ~IEEE80211_CONF_PS;
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ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
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}
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if (!(local->scan_ps_enabled) ||
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!(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
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/*
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* If power save was enabled, no need to send a nullfunc
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* frame because AP knows that we are sleeping. But if the
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* hardware is creating the nullfunc frame for power save
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* status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
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* enabled) and power save was enabled, the firmware just
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* sent a null frame with power save disabled. So we need
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* to send a new nullfunc frame to inform the AP that we
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* are again sleeping.
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*/
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ieee80211_send_nullfunc(local, sdata, 1);
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}
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/* inform AP that we are awake again, unless power save is enabled */
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static void ieee80211_scan_ps_disable(struct ieee80211_sub_if_data *sdata)
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{
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struct ieee80211_local *local = sdata->local;
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if (!local->ps_sdata)
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ieee80211_send_nullfunc(local, sdata, 0);
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else if (local->scan_ps_enabled) {
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/*
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* In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
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* will send a nullfunc frame with the powersave bit set
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* even though the AP already knows that we are sleeping.
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* This could be avoided by sending a null frame with power
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* save bit disabled before enabling the power save, but
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* this doesn't gain anything.
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*
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* When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
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* to send a nullfunc frame because AP already knows that
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* we are sleeping, let's just enable power save mode in
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* hardware.
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*/
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local->hw.conf.flags |= IEEE80211_CONF_PS;
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ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
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} else if (local->hw.conf.dynamic_ps_timeout > 0) {
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/*
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* If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
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* had been running before leaving the operating channel,
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* restart the timer now and send a nullfunc frame to inform
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* the AP that we are awake.
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*/
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ieee80211_send_nullfunc(local, sdata, 0);
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mod_timer(&local->dynamic_ps_timer, jiffies +
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msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
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}
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}
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void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
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{
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struct ieee80211_local *local = hw_to_local(hw);
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struct ieee80211_sub_if_data *sdata;
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bool was_hw_scan;
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mutex_lock(&local->scan_mtx);
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/*
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* It's ok to abort a not-yet-running scan (that
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* we have one at all will be verified by checking
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* local->scan_req next), but not to complete it
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* successfully.
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*/
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if (WARN_ON(!local->scanning && !aborted))
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aborted = true;
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if (WARN_ON(!local->scan_req)) {
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mutex_unlock(&local->scan_mtx);
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return;
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}
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was_hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
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if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) {
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ieee80211_queue_delayed_work(&local->hw,
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&local->scan_work, 0);
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mutex_unlock(&local->scan_mtx);
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return;
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}
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kfree(local->hw_scan_req);
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local->hw_scan_req = NULL;
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if (local->scan_req != local->int_scan_req)
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cfg80211_scan_done(local->scan_req, aborted);
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local->scan_req = NULL;
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local->scan_sdata = NULL;
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local->scanning = 0;
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local->scan_channel = NULL;
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/* we only have to protect scan_req and hw/sw scan */
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mutex_unlock(&local->scan_mtx);
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ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
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if (was_hw_scan)
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goto done;
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ieee80211_configure_filter(local);
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drv_sw_scan_complete(local);
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mutex_lock(&local->iflist_mtx);
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list_for_each_entry(sdata, &local->interfaces, list) {
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if (!netif_running(sdata->dev))
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continue;
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/* Tell AP we're back */
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if (sdata->vif.type == NL80211_IFTYPE_STATION) {
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if (sdata->u.mgd.associated) {
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ieee80211_scan_ps_disable(sdata);
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netif_tx_wake_all_queues(sdata->dev);
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}
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} else
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netif_tx_wake_all_queues(sdata->dev);
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/* re-enable beaconing */
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if (sdata->vif.type == NL80211_IFTYPE_AP ||
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sdata->vif.type == NL80211_IFTYPE_ADHOC ||
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sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
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ieee80211_bss_info_change_notify(
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sdata, BSS_CHANGED_BEACON_ENABLED);
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}
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mutex_unlock(&local->iflist_mtx);
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done:
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ieee80211_recalc_idle(local);
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ieee80211_mlme_notify_scan_completed(local);
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ieee80211_ibss_notify_scan_completed(local);
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ieee80211_mesh_notify_scan_completed(local);
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}
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EXPORT_SYMBOL(ieee80211_scan_completed);
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static int ieee80211_start_sw_scan(struct ieee80211_local *local)
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{
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struct ieee80211_sub_if_data *sdata;
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/*
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* Hardware/driver doesn't support hw_scan, so use software
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* scanning instead. First send a nullfunc frame with power save
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* bit on so that AP will buffer the frames for us while we are not
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* listening, then send probe requests to each channel and wait for
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* the responses. After all channels are scanned, tune back to the
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* original channel and send a nullfunc frame with power save bit
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* off to trigger the AP to send us all the buffered frames.
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*
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* Note that while local->sw_scanning is true everything else but
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* nullfunc frames and probe requests will be dropped in
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* ieee80211_tx_h_check_assoc().
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*/
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drv_sw_scan_start(local);
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mutex_lock(&local->iflist_mtx);
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list_for_each_entry(sdata, &local->interfaces, list) {
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if (!netif_running(sdata->dev))
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continue;
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/* disable beaconing */
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if (sdata->vif.type == NL80211_IFTYPE_AP ||
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sdata->vif.type == NL80211_IFTYPE_ADHOC ||
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sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
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ieee80211_bss_info_change_notify(
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sdata, BSS_CHANGED_BEACON_ENABLED);
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/*
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* only handle non-STA interfaces here, STA interfaces
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* are handled in the scan state machine
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*/
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if (sdata->vif.type != NL80211_IFTYPE_STATION)
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netif_tx_stop_all_queues(sdata->dev);
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}
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mutex_unlock(&local->iflist_mtx);
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local->next_scan_state = SCAN_DECISION;
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local->scan_channel_idx = 0;
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ieee80211_configure_filter(local);
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/* TODO: start scan as soon as all nullfunc frames are ACKed */
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ieee80211_queue_delayed_work(&local->hw,
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&local->scan_work,
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IEEE80211_CHANNEL_TIME);
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return 0;
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}
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static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
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struct cfg80211_scan_request *req)
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{
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struct ieee80211_local *local = sdata->local;
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struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
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int rc;
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if (local->scan_req)
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return -EBUSY;
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if (req != local->int_scan_req &&
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sdata->vif.type == NL80211_IFTYPE_STATION &&
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!list_empty(&ifmgd->work_list)) {
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/* actually wait for the work it's doing to finish/time out */
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set_bit(IEEE80211_STA_REQ_SCAN, &ifmgd->request);
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local->scan_req = req;
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local->scan_sdata = sdata;
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return 0;
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}
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if (local->ops->hw_scan) {
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u8 *ies;
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local->hw_scan_req = kmalloc(
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sizeof(*local->hw_scan_req) +
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req->n_channels * sizeof(req->channels[0]) +
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2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len +
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req->ie_len, GFP_KERNEL);
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if (!local->hw_scan_req)
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return -ENOMEM;
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local->hw_scan_req->ssids = req->ssids;
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local->hw_scan_req->n_ssids = req->n_ssids;
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ies = (u8 *)local->hw_scan_req +
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sizeof(*local->hw_scan_req) +
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req->n_channels * sizeof(req->channels[0]);
|
|
local->hw_scan_req->ie = ies;
|
|
|
|
local->hw_scan_band = 0;
|
|
}
|
|
|
|
local->scan_req = req;
|
|
local->scan_sdata = sdata;
|
|
|
|
if (local->ops->hw_scan)
|
|
__set_bit(SCAN_HW_SCANNING, &local->scanning);
|
|
else
|
|
__set_bit(SCAN_SW_SCANNING, &local->scanning);
|
|
/*
|
|
* Kicking off the scan need not be protected,
|
|
* only the scan variable stuff, since now
|
|
* local->scan_req is assigned and other callers
|
|
* will abort their scan attempts.
|
|
*
|
|
* This avoids getting a scan_mtx -> iflist_mtx
|
|
* dependency, so that the scan completed calls
|
|
* have more locking freedom.
|
|
*/
|
|
|
|
ieee80211_recalc_idle(local);
|
|
mutex_unlock(&local->scan_mtx);
|
|
|
|
if (local->ops->hw_scan) {
|
|
WARN_ON(!ieee80211_prep_hw_scan(local));
|
|
rc = drv_hw_scan(local, local->hw_scan_req);
|
|
} else
|
|
rc = ieee80211_start_sw_scan(local);
|
|
|
|
mutex_lock(&local->scan_mtx);
|
|
|
|
if (rc) {
|
|
kfree(local->hw_scan_req);
|
|
local->hw_scan_req = NULL;
|
|
local->scanning = 0;
|
|
|
|
ieee80211_recalc_idle(local);
|
|
|
|
local->scan_req = NULL;
|
|
local->scan_sdata = NULL;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
static int ieee80211_scan_state_decision(struct ieee80211_local *local,
|
|
unsigned long *next_delay)
|
|
{
|
|
bool associated = false;
|
|
struct ieee80211_sub_if_data *sdata;
|
|
|
|
/* if no more bands/channels left, complete scan and advance to the idle state */
|
|
if (local->scan_channel_idx >= local->scan_req->n_channels) {
|
|
ieee80211_scan_completed(&local->hw, false);
|
|
return 1;
|
|
}
|
|
|
|
/* check if at least one STA interface is associated */
|
|
mutex_lock(&local->iflist_mtx);
|
|
list_for_each_entry(sdata, &local->interfaces, list) {
|
|
if (!netif_running(sdata->dev))
|
|
continue;
|
|
|
|
if (sdata->vif.type == NL80211_IFTYPE_STATION) {
|
|
if (sdata->u.mgd.associated) {
|
|
associated = true;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
mutex_unlock(&local->iflist_mtx);
|
|
|
|
if (local->scan_channel) {
|
|
/*
|
|
* we're currently scanning a different channel, let's
|
|
* switch back to the operating channel now if at least
|
|
* one interface is associated. Otherwise just scan the
|
|
* next channel
|
|
*/
|
|
if (associated)
|
|
local->next_scan_state = SCAN_ENTER_OPER_CHANNEL;
|
|
else
|
|
local->next_scan_state = SCAN_SET_CHANNEL;
|
|
} else {
|
|
/*
|
|
* we're on the operating channel currently, let's
|
|
* leave that channel now to scan another one
|
|
*/
|
|
local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL;
|
|
}
|
|
|
|
*next_delay = 0;
|
|
return 0;
|
|
}
|
|
|
|
static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local,
|
|
unsigned long *next_delay)
|
|
{
|
|
struct ieee80211_sub_if_data *sdata;
|
|
|
|
/*
|
|
* notify the AP about us leaving the channel and stop all STA interfaces
|
|
*/
|
|
mutex_lock(&local->iflist_mtx);
|
|
list_for_each_entry(sdata, &local->interfaces, list) {
|
|
if (!netif_running(sdata->dev))
|
|
continue;
|
|
|
|
if (sdata->vif.type == NL80211_IFTYPE_STATION) {
|
|
netif_tx_stop_all_queues(sdata->dev);
|
|
if (sdata->u.mgd.associated)
|
|
ieee80211_scan_ps_enable(sdata);
|
|
}
|
|
}
|
|
mutex_unlock(&local->iflist_mtx);
|
|
|
|
__set_bit(SCAN_OFF_CHANNEL, &local->scanning);
|
|
|
|
/* advance to the next channel to be scanned */
|
|
*next_delay = HZ / 10;
|
|
local->next_scan_state = SCAN_SET_CHANNEL;
|
|
}
|
|
|
|
static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local,
|
|
unsigned long *next_delay)
|
|
{
|
|
struct ieee80211_sub_if_data *sdata = local->scan_sdata;
|
|
|
|
/* switch back to the operating channel */
|
|
local->scan_channel = NULL;
|
|
ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
|
|
|
|
/*
|
|
* notify the AP about us being back and restart all STA interfaces
|
|
*/
|
|
mutex_lock(&local->iflist_mtx);
|
|
list_for_each_entry(sdata, &local->interfaces, list) {
|
|
if (!netif_running(sdata->dev))
|
|
continue;
|
|
|
|
/* Tell AP we're back */
|
|
if (sdata->vif.type == NL80211_IFTYPE_STATION) {
|
|
if (sdata->u.mgd.associated)
|
|
ieee80211_scan_ps_disable(sdata);
|
|
netif_tx_wake_all_queues(sdata->dev);
|
|
}
|
|
}
|
|
mutex_unlock(&local->iflist_mtx);
|
|
|
|
__clear_bit(SCAN_OFF_CHANNEL, &local->scanning);
|
|
|
|
*next_delay = HZ / 5;
|
|
local->next_scan_state = SCAN_DECISION;
|
|
}
|
|
|
|
static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
|
|
unsigned long *next_delay)
|
|
{
|
|
int skip;
|
|
struct ieee80211_channel *chan;
|
|
|
|
skip = 0;
|
|
chan = local->scan_req->channels[local->scan_channel_idx];
|
|
|
|
local->scan_channel = chan;
|
|
if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
|
|
skip = 1;
|
|
|
|
/* advance state machine to next channel/band */
|
|
local->scan_channel_idx++;
|
|
|
|
if (skip) {
|
|
/* if we skip this channel return to the decision state */
|
|
local->next_scan_state = SCAN_DECISION;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Probe delay is used to update the NAV, cf. 11.1.3.2.2
|
|
* (which unfortunately doesn't say _why_ step a) is done,
|
|
* but it waits for the probe delay or until a frame is
|
|
* received - and the received frame would update the NAV).
|
|
* For now, we do not support waiting until a frame is
|
|
* received.
|
|
*
|
|
* In any case, it is not necessary for a passive scan.
|
|
*/
|
|
if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN ||
|
|
!local->scan_req->n_ssids) {
|
|
*next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
|
|
local->next_scan_state = SCAN_DECISION;
|
|
return;
|
|
}
|
|
|
|
/* active scan, send probes */
|
|
*next_delay = IEEE80211_PROBE_DELAY;
|
|
local->next_scan_state = SCAN_SEND_PROBE;
|
|
}
|
|
|
|
static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
|
|
unsigned long *next_delay)
|
|
{
|
|
int i;
|
|
struct ieee80211_sub_if_data *sdata = local->scan_sdata;
|
|
|
|
for (i = 0; i < local->scan_req->n_ssids; i++)
|
|
ieee80211_send_probe_req(
|
|
sdata, NULL,
|
|
local->scan_req->ssids[i].ssid,
|
|
local->scan_req->ssids[i].ssid_len,
|
|
local->scan_req->ie, local->scan_req->ie_len);
|
|
|
|
/*
|
|
* After sending probe requests, wait for probe responses
|
|
* on the channel.
|
|
*/
|
|
*next_delay = IEEE80211_CHANNEL_TIME;
|
|
local->next_scan_state = SCAN_DECISION;
|
|
}
|
|
|
|
void ieee80211_scan_work(struct work_struct *work)
|
|
{
|
|
struct ieee80211_local *local =
|
|
container_of(work, struct ieee80211_local, scan_work.work);
|
|
struct ieee80211_sub_if_data *sdata = local->scan_sdata;
|
|
unsigned long next_delay = 0;
|
|
|
|
mutex_lock(&local->scan_mtx);
|
|
if (!sdata || !local->scan_req) {
|
|
mutex_unlock(&local->scan_mtx);
|
|
return;
|
|
}
|
|
|
|
if (local->hw_scan_req) {
|
|
int rc = drv_hw_scan(local, local->hw_scan_req);
|
|
mutex_unlock(&local->scan_mtx);
|
|
if (rc)
|
|
ieee80211_scan_completed(&local->hw, true);
|
|
return;
|
|
}
|
|
|
|
if (local->scan_req && !local->scanning) {
|
|
struct cfg80211_scan_request *req = local->scan_req;
|
|
int rc;
|
|
|
|
local->scan_req = NULL;
|
|
local->scan_sdata = NULL;
|
|
|
|
rc = __ieee80211_start_scan(sdata, req);
|
|
mutex_unlock(&local->scan_mtx);
|
|
|
|
if (rc)
|
|
ieee80211_scan_completed(&local->hw, true);
|
|
return;
|
|
}
|
|
|
|
mutex_unlock(&local->scan_mtx);
|
|
|
|
/*
|
|
* Avoid re-scheduling when the sdata is going away.
|
|
*/
|
|
if (!netif_running(sdata->dev)) {
|
|
ieee80211_scan_completed(&local->hw, true);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* as long as no delay is required advance immediately
|
|
* without scheduling a new work
|
|
*/
|
|
do {
|
|
switch (local->next_scan_state) {
|
|
case SCAN_DECISION:
|
|
if (ieee80211_scan_state_decision(local, &next_delay))
|
|
return;
|
|
break;
|
|
case SCAN_SET_CHANNEL:
|
|
ieee80211_scan_state_set_channel(local, &next_delay);
|
|
break;
|
|
case SCAN_SEND_PROBE:
|
|
ieee80211_scan_state_send_probe(local, &next_delay);
|
|
break;
|
|
case SCAN_LEAVE_OPER_CHANNEL:
|
|
ieee80211_scan_state_leave_oper_channel(local, &next_delay);
|
|
break;
|
|
case SCAN_ENTER_OPER_CHANNEL:
|
|
ieee80211_scan_state_enter_oper_channel(local, &next_delay);
|
|
break;
|
|
}
|
|
} while (next_delay == 0);
|
|
|
|
ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
|
|
}
|
|
|
|
int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
|
|
struct cfg80211_scan_request *req)
|
|
{
|
|
int res;
|
|
|
|
mutex_lock(&sdata->local->scan_mtx);
|
|
res = __ieee80211_start_scan(sdata, req);
|
|
mutex_unlock(&sdata->local->scan_mtx);
|
|
|
|
return res;
|
|
}
|
|
|
|
int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata,
|
|
const u8 *ssid, u8 ssid_len)
|
|
{
|
|
struct ieee80211_local *local = sdata->local;
|
|
int ret = -EBUSY;
|
|
|
|
mutex_lock(&local->scan_mtx);
|
|
|
|
/* busy scanning */
|
|
if (local->scan_req)
|
|
goto unlock;
|
|
|
|
memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
|
|
local->int_scan_req->ssids[0].ssid_len = ssid_len;
|
|
|
|
ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
|
|
unlock:
|
|
mutex_unlock(&local->scan_mtx);
|
|
return ret;
|
|
}
|
|
|
|
void ieee80211_scan_cancel(struct ieee80211_local *local)
|
|
{
|
|
bool abortscan;
|
|
|
|
cancel_delayed_work_sync(&local->scan_work);
|
|
|
|
/*
|
|
* Only call this function when a scan can't be
|
|
* queued -- mostly at suspend under RTNL.
|
|
*/
|
|
mutex_lock(&local->scan_mtx);
|
|
abortscan = test_bit(SCAN_SW_SCANNING, &local->scanning) ||
|
|
(!local->scanning && local->scan_req);
|
|
mutex_unlock(&local->scan_mtx);
|
|
|
|
if (abortscan)
|
|
ieee80211_scan_completed(&local->hw, true);
|
|
}
|